1. Field of the Invention
The invention disclosed herein relates generally to performing storage operations on electronic data in a computer network. More particularly, the present invention relates to integrating storage-related operations for a computer network according to a specified arrangement of storage operation cells.
2. Description of the Related Art
Current storage management systems employ a number of different methods to perform storage operations on electronic data. For example, data can be stored in primary storage as a primary copy or in secondary storage as various types of secondary copies including, as a backup copy, a snapshot copy, a hierarchical storage management copy (“HSM”), as an archive copy, and as other types of copies.
A primary copy of data is generally a production copy or other “live” version of the data which is used by a software application and is generally in the native format of that application. Primary copy data may be maintained in a local memory or other high-speed storage device that allows for relatively fast data access if necessary. Such primary copy data is typically intended for short term retention (e.g., several hours or days) before some or all of the data is stored as one or more secondary copies, for example to prevent loss of data in the event a problem occurred with the data stored in primary storage.
Secondary copies include point-in-time data and are typically for intended for long-term retention (e.g., weeks, months or years depending on retention criteria, for example as specified in a storage policy as further described herein) before some or all of the data is moved to other storage or discarded. Secondary copies may be indexed so users can browse and restore the data at another point in time. After certain primary copy data is backed up, a pointer or other location indicia such as a stub may be placed in the primary copy to indicate the current location of that data.
One type of secondary copy is a backup copy. A backup copy is generally a point-in-time copy of the primary copy data stored in a backup format as opposed to in native application format. For example, a backup copy may be stored in a backup format that is optimized for compression and efficient long-term storage. Backup copies generally have relatively long retention periods and may be stored on media with slower retrieval times than other types of secondary copies and media. In some cases, backup copies may be stored at on offsite location.
Another form of secondary copy is a snapshot copy. From an end-user viewpoint, a snapshot may be thought as an instant image of the primary copy data at a given point in time. A snapshot generally captures the directory structure of a primary copy volume at a particular moment in time, and also preserves file attributes and contents. In some embodiments, a snapshot may exist as a virtual file system, parallel to the actual file system. Users typically gain a read-only access to the record of files and directories of the snapshot. By electing to restore primary copy data from a snapshot taken at a given point in time, users may also return the current file system to the prior state of the file system that existed when the snapshot was taken.
A snapshot may be created instantly, using a minimum of file space, but may still function as a conventional file system backup. A snapshot may not actually create another physical copy of all the data, but may simply create pointers that are able to map files and directories to specific disk blocks.
In some embodiments, once a snapshot has been taken, subsequent changes to the file system typically do not overwrite the blocks in use at the time of snapshot. Therefore, the initial snapshot may use only a small amount of disk space needed to record a mapping or other data structure representing or otherwise tracking the blocks that correspond to the current state of the file system. Additional disk space is usually only required when files and directories are actually modified later. Furthermore, when files are modified, typically only the pointers which map to blocks are copied, not the blocks themselves. In some embodiments, for example in the case of copy-on-write snapshots, when a block changes in primary storage, the block is copied to secondary storage before the block is overwritten in primary storage and the snapshot mapping of file system data is updated to reflect the changed block(s) at that particular point in time. An HSM copy is generally a copy of the primary copy data, but typically includes only a subset of the primary copy data that meets a certain criteria and is usually stored in a format other than the native application format. For example, an HSM copy might include only that data from the primary copy that is larger than a given size threshold or older than a given age threshold and that is stored in a backup format. Often, HSM data is removed from the primary copy, and a stub is stored in the primary copy to indicate its new location. When a user requests access to the HSM data that has been removed or migrated, systems use the stub to locate the data and often make recovery of the data appear transparent even though the HSM data may be stored at a location different from the remaining primary copy data.
An archive copy is generally similar to an HSM copy, however, the data satisfying criteria for removal from the primary copy is generally completely removed with no stub left in the primary copy to indicate the new location (i.e., where it has been moved to). Archive copies of data are generally stored in a backup format or other nonnative application format. In addition, archive copies are generally retained for very long periods of time (e.g., years) and in some cases are never deleted. Such archive copies may be made and kept for extended periods in order to meet compliance regulations or for other permanent storage applications.
In some embodiments, application data over its lifetime moves from more expensive quick access storage to less expensive slower access storage. This process of moving data through these various tiers of storage is sometimes referred to as information lifecycle management (“ILM”). This is the process by which data is “aged” from more forms of secondary storage with faster access/restore times down through less expensive secondary storage with slower access/restore times, for example, as the data becomes less important or mission critical over time.
Examples of various types of data and copies of data are further described in the above-referenced related applications that are hereby incorporated by reference in their entirety. One example of a system that performs storage operations on electronic data that produce such copies is the QiNetix storage management system by CommVault Systems of Oceanport, N.J.
The QiNetix system leverages a modular storage management architecture that may include, among other things, storage manager components, client or data agent components, and media agent components as further described in U.S. patent application Ser. No. 10/818,749 which is hereby incorporated herein by reference in its entirety. The QiNetix system also may be hierarchically configured into backup cells to store and retrieve backup copies of electronic data as further described in U.S. patent application Ser. No. 09/354,058 which is hereby incorporated by reference in its entirety.
Backup systems may be improved by providing systems and methods to hierarchically configure backup cells to perform certain other types of storage operations including snapshot copies, HSM copies, archive copies, and certain other types of copies of electronic data.
A further shortcoming of prior art storage systems relates to the lack of meaningful integration between and among HSM systems and Storage Resource Management (“SRM”) systems. SRM systems are typically concerned with monitoring the health, status, and other information associated with primary copies of data (e.g., live or production line copies). For example, an SRM application may monitor the capacity of a volume storing a primary copy of data and the rate of data transfer relative to the available storage of that volume. In contrast, HSM systems are typically concerned with data transport to secondary storage, such as the parameters and particulars associated with the storage and migration of secondary copy data as opposed to monitoring of information associated with primary copy data. HSM systems are thus generally directed to secondary copies and other archival data volumes. For example, an HSM system may be directed to migrating or otherwise transferring data to a secondary copy.
Existing SRM systems, however, do not meaningfully interoperate with existing HSM systems across an enterprise or network. For example, although an SRM system may monitor the available space of a primary storage volume and note when its capacity is being reached (or exceeded), the SRM system itself is typically incapable of initiating any substantive corrective or preventative action. Similarly, because an HSM system is typically concerned only with migrating and managing secondary copy data to secondary volumes and data stores, it is therefore generally unaware of conditions or problems associated with primary copy data. In the past, to address this problem, users have implemented two distinct SRM and HSM systems and manually handled issues discovered by SRM systems when HSM support or other input is required or vice versa. Thus, in view of the foregoing, it would be desirable to provide systems and methods that more meaningfully integrate SRM and HSM components in storage management systems to perform autonomous or pseudo-autonomous storage operations and other operations.